SQL AS Keyword
AS command is used to rename a column or table with an alias.
An alias only exists for the duration of the query.
Alias for Columns
The following SQL statement creates two aliases, one for the CustomerID column and one for the CustomerName column:
The following SQL statement creates two aliases. Notice that it requires double quotation marks or square brackets if the alias name contains spaces:
The following SQL statement creates an alias named "Address" that combine four columns (Address, PostalCode, City and Country):
Note: To get the SQL statement above to work in MySQL use the following:
Alias for Tables
The following SQL statement selects all the orders from the customer with CustomerID=4 (Around the Horn). We use the "Customers" and "Orders" tables, and give them the table aliases of "c" and "o" respectively (Here we use aliases to make the SQL shorter):
FROM Customers AS c, Orders AS o
WHERE c.CustomerName="Around the Horn" AND c.CustomerID=o.CustomerID;